Carlos Benito Jones, 25, and Isidro Santiago Jones, 20, are each charged with one count of first-degree murder in the death of 34-year-old Zorana Lebedic, who was gunned down at Palmetto Street and Fairburn Avenue as she biked home from a Scientology class in downtown Clearwater.

The brothers, of Clearwater, are already facing charges connected to the fatal Oct. 15 shootings of Colbert Collins, 58, of Clearwater and Peter Rakowski, 46, of New York. The shootings occurred in the area of Cherry Harris Park, formerly called Marshall Park, on Beckett Street in the North Greenwood area, around 4:45 a.m.

Ballistics tests confirmed the same gun was used in both shootings, Clearwater police said.

Both men have been held in the Pinellas County Jail without bond since their arrests on separate days in October and November.

The brothers are also facing charges from the Pinellas County Sheriff's Office in connection with a robbery that happened in Dunedin about 45 minutes before Lebedic was shot, authorities said.

Around 10:20 p.m., two men robbed a 34-year-old man walking on Beltrees Street near Louden Avenue in Dunedin, which is about 2 1/2 miles north of the Clearwater shooting.

In that case, one of the men pointed a dark-colored handgun at the man and took his cellphone, authorities said. The two men then drove off in a tan or beige sedan that resembled an unmarked police car.

Witnesses described a similar car at the scene of Lebedic's slaying.

Lebedic, of 1799 N Highland Ave., Apt. 60, was fatally shot in the torso just after 11 p.m. Sept. 25 a block east of Clearwater Intermediate School in a residential neighborhood just west of N Betty Lane.

A nearby neighbor, who peeked through his blinds after hearing a gunshot, said he saw a passing van stop moments after the shooting. Two men got out to try to help the woman, then flagged down another passing motorist. The trio tried to perform CPR, neighbor Eric Townsend said.

About three weeks later, on Oct. 15, a witness said he was riding his bicycle near Cherry Harris Park around 4:45 a.m. when he saw Carlos Jones and two other men pull up in a white car and get out. Jones and one of the men from the vehicle approached Collins and spoke to him, the witness said.

The witness said he overheard Collins say, "No," at which point Jones pulled a handgun from his waistband and started shooting at Collins and the other victim, the warrant states.

The witness, a 48-year-old man who was not identified, said the other man — later identified as Isidro Jones — also started shooting at Collins.

Police said the park slaying was drug-related. The motive in the Palmetto Street shooting was robbery, said Clearwater police spokeswoman Elizabeth Watts.

"They approached (Lebedic) and tried to rob her of her backpack and she fought back, trying not to give it up, and they shot and killed her," Watts said.

Clearwater police found Lebedic's bicycle and a backpack near her body after the shooting.